COMMUNICATION PARTNER APPLIANCE WITH AUTOMATIC SEND MODE ACTIVATION

Description

[0001] The invention relates to a circuit, this circuit being provided for a communication partner appliance that is designed for contact less communication, this communication partner appliance being provided for a communication system with at least one further communication partner appliance, in which circuit a first communication mode or a second communication mode can be activated.

[0002] The invention furthermore relates to a communication partner appliance that is designed as a data carrier and contains a circuit as described above in the first paragraph.

[0003] The invention furthermore relates to a circuit, this circuit being provided for a communication partner appliance that is designed for contact less communication, this communication partner appliance being provided for a communication system with at least one further communication partner appliance, this circuit containing the means listed below: production means for producing a carrier signal and transmission means for transmitting the carrier signal to the further communication partner appliance.

[0004] The invention furthermore relates to a communication partner appliance that is designed as a communication station and includes a circuit as described above in the third paragraph.

[0005] The invention furthermore relates to a method of activating a first communication mode or a second communication mode of a communication partner appliance, wherein the communication partner appliance is provided for a communication system with at least one further communication partner appliance, and wherein a carrier signal is transmitted by the at least one further communication partner appliance, this carrier signal being received with the communication partner appliance.

[0006] Such a circuit of the type described in the first paragraph above, and such a communication partner appliance of the type described at the outset in the second paragraph, which has such a circuit, and such a method, are known from the patent document US 6,466,771. In an embodiment, the known document discloses a transponder with a circuit, with the transponder and/or the circuit being designed so as to be capable of being switched over, namely between a passive communication mode and an active communication mode. It is also known from the document that the further communication partner appliance is designed as a reader station or communication station for transmitting a carrier signal.

[0007] In the case of the transponder, in the case of the active communication mode a power supply for the circuit is provided that is independent of the carrier signal, and in the case of the passive communication mode a power supply for the circuit is provided, which power supply is dependent on the carrier signal in a known manner. The known transponder or the known circuit has command signal recognition means for recognizing and processing command signals, these command signals being generated in the further communication partner appliance and being transmitted with the aid of the carrier signal. Switching over between the passive communication mode and the active communication mode takes place through a special command signal which is transmitted by the further communication partner appliance and which is designed as a change-over command signal.

[0008] A disadvantage in the case of this known transponder and method is that a desired flexibility of deployment or usability in other communication systems is subject to limits or is not possible, for example in those communication systems in which the reader station cannot generate or transmit a change-over command signal.

[0009] A further disadvantage is that a relatively large and complicated and therefore error-prone control arrangement is required, and in fact in both the transponder and in the reader station.

[0010] It is an object of the invention to eliminate the disadvantages mentioned above, and to realize an improved method and an improved circuit for a communication partner appliance designed as a data carrier, and an improved communication partner appliance designed as a data carrier, and an improved circuit for a communication partner appliance designed as a communication station, and an improved communication partner appliance designed as a communication station.

[0011] To achieve the object stated above, in the case of a circuit for a communication partner appliance which is designed as data carrier and which is in accordance with the invention, features in accordance with the invention are provided, so that such a circuit according to the invention can be characterized in the following manner, namely:

[0012] A circuit, this circuit being provided for a communication partner appliance that is designed for contact less communication and as a data carrier, this communication partner appliance being provided for a communication system with at least one further communication partner appliance, in which circuit a first communication mode or a second communication mode can be activated, and which circuit has the means listed below:

• activators for activating the first communication mode or the second communication mode, and reception means for receiving a carrier signal that is transmitted by the at least one further communication partner appliance, and detectors for detecting the presence of the received carrier signal, these detectors transmitting a carrier signal present signal in the event that the carrier signal is present, and otherwise transmitting a carrier signal not-present signal, and command signal recognition means for recognizing a command signal that can be transmitted with the aid of the carrier signal and for transmitting a command-end signal that represents the end of the transmitted command signal, and determination means for determining whether, after the occurrence of the command-end signal, at a given measurement point in time, the carrier signal present signal is present, with which determination means a first activation signal can be transmitted when the carrier signal present signal is present, and otherwise a second activation signal can be transmitted, with which first activation signal the circuit can be brought into the first communication mode with the aid of the activators, and with which second activation signal the circuit can be brought into the second communication mode with the aid of the activators.

[0013] To achieve the object stated above, furthermore in the case of a communication partner appliance according to the invention, which is designed as a data carrier, features according to the invention are provided, so that such a communication partner appliance according to the invention can be characterized in the following manner, namely:

A communication partner appliance that is designed as a data carrier and is equipped with a circuit as claimed in one of the claims 1 to 3.

[0014] To achieve the object stated above, furthermore in the case of a circuit for a communication partner appliance according to the invention that is designed as a communication station, features according to the invention are provided, so that such a circuit according to the invention can be characterized in the following manner, namely:

A circuit, this circuit being provided for a communication partner appliance that is designed for contact less communication and as a communication station, this communication partner appliance being provided for a communication system with at least one further communication partner appliance, in which further communication partner appliance a first communication mode or a second communication mode can be activated, this circuit containing the means listed below:

• production means for producing a carrier signal, and transmission means for transmitting the carrier signal to the further communication partner appliance, and
• arranging means for arranging a communication mode, and a generator for generating at least one command signal, which command signal can be transmitted to the further communication partner appliance with the aid of the carrier signal, and
• first control elements for transmitting a command-end signal that represents the end of the generated command signal, and second control elements with which second control elements, after the occurrence of the command-end signal, the generation and/or transmission of the carrier signal can be ended at a particular point in time.

[0015] To achieve the object stated above, furthermore in the case of a communication partner appliance according to the invention that is designed as a communication station, features according to the invention are provided so that such a communication partner appliance according to the invention can be characterized in the following manner, namely:

A communication partner appliance that is designed as a communication station and is equipped with a circuit as claimed in any one of the claims 5 to 9.

To achieve the object stated above, in the case of a method according to the invention, features according to the invention are provided, such that a method according to the invention can be characterized in the following manner, namely:

A method for activating a first communication mode or a second communication mode of a communication partner appliance, wherein the communication partner appliance is provided for a communication system with at least one further communication partner appliance, and wherein a carrier signal is transmitted by the at least one further communication partner appliance, this carrier signal being received with the communication partner appliance, and
- wherein in the communication partner appliance, detection of the presence of the received carrier signal takes place, and in the event of the carrier signal being present, a carrier signal present signal is transmitted, and otherwise a carrier signal not-present signal, and wherein recognition of a command signal that can be transmitted with the aid of the carrier signal takes place, and the transmission of a command-end signal that represents the end of the transmitted command signal takes place, and wherein determination is carried out to see whether, after the occurrence of the command-end signal, at a measurement point in time, the carrier signal present signal is present, wherein a first activation signal is transmitted when the carrier signal present signal is present, and otherwise a second activation signal is transmitted, and wherein with the first activation signal, activation of the communication partner appliance into the first communication mode is carried out, or with the second activation signal an activation of the communication partner appliance into the second communication mode is carried out.

[0016] Through the provision of the features according to the invention, it is achieved in an advantageous and easily realized manner that where communication partner appliances are used which, in accordance with the invention, are designed as a communication station, and which enter into communication in a communication system with communication partner appliances designed as data carriers, the communication partner appliances designed as data carriers automatically recognize in which communication mode a communication response of the communication partner appliances designed as data carriers should take place, i.e. for example whether the response should be made in an active transmission or communication mode, or in a passive transmission or communication mode. Furthermore, on account of the measures according to the invention, an advantage is achieved in particular where a communication partner appliance is designed as both a communication station and a data carrier, through which diverse deployment in various communication systems is possible. Thus for example in a so-called "Near Field Communication" (NFC) system, two communication partner appliances that are designed as both a communication station and a data carrier can communicate with one another, wherein one of the two communication partner appliances is activated as a communication station and exchanges data with the other communication partner appliance. Such communication partner appliances are mostly designed as mobile devices, and have a mobile power supply source. As a result of considerations of energy consumption in the case of such communication partner appliances, it must be noted that an optimum, energy-saving power supply is achieved when both communication partner appliances have their own power supply activated during communication. On the other hand, such communication partner appliances according to the invention can be used to advantage in, for example, an entry monitoring system, in which entry monitoring system an entry-monitoring communication station communicates with communication partner appliances which in accordance with the invention are designed as data carriers, wherein the entry-monitoring communication station has a fixed power supply, in other words to a certain extent there is an inexhaustible energy source, and wherein the data carriers can, advantageously, communicate in the passive communication mode, and thus conserve their own energy source, which own energy source is limited in terms of energy output.

[0017] In the case of a communication station according to the invention, the communication mode can be arranged by an arranging action that is carried out by a user or support technician. It has been shown to be particularly advantageous if, in addition, the measures as claimed in claim 7 are provided. Through this, automatic switch-over of the communication mode can be carried out, depending on a power supply of the communication station.

[0018] In the case of a communication station according to the invention, it has been proven to be advantageous if, in addition, the measures as claimed in claim 8 are provided. This provides greater flexibility in communication with communication partner appliances. For example, in the case where an inquiry is made of a data carrier by the communication station in an active communication mode, [and] this data carrier does not or cannot emit a response signal because the relevant data carrier has no suitable power supply of its own for communicating in the active communication mode or, if there is an energy source, this power supply is no longer sufficient, and wherein as a consequence of the missing response signal, the passive communication mode is set in the communication station.

[0019] In the case of a communication station according to the invention, it has been shown to be advantageous if, in addition, the measures as claimed in claim 9 are provided. Through this, a favorable energy balance of the power supplies of the communication partner appliances can be achieved.

[0020] These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

[0021] The invention will be described in greater detail below, on the basis of the embodiments shown in the drawings, to which however the invention is not restricted.

[0022] Fig. 1 shows schematically, in the form of a block diagram, those parts of communication partner appliances according to the invention that are important in the present connection, these communication partner appliances each containing a circuit according to the invention.

[0023] Fig. 2 shows a deployment of a communication partner appliance according to the invention in an entry-monitoring communication system.

[0024] Fig. 3 shows a deployment of a communication partner appliance according to the invention in a further communication system.

[0025] Fig. 4 shows, schematically, commands and signals that are transmitted between the communication partner appliances.

[0026] Figure 1 shows a communication system 1 with communication partner appliances in a communication area CA, this communication area CA being indicated by a broken line. In the following, the communication partner appliances are referred to as devices, for brevity. Here, one device is designed as a data carrier 2 and a further device is designed as a communication station or reader station 3.

[0027] The reader station 3 is designed for contact less communication with the data carrier 2. The data carrier 2 has a circuit 4, in which circuit 4 either a first communication mode or a second communication mode can be activated, which is explained in greater detail below.

[0028] In this case, the reader station 3 is a portion of a portable small computer, in other words a PDA, and contains a station circuit 5, this station circuit 5 being designed as an integrated circuit and containing a station micro-computer 6. The station micro-computer 6 contains a central processing unit 7 and station storage media 8, this central processing unit 7 and station storage media 8 working together in a familiar manner. The station micro-computer 6 is furthermore connected to a main computer of the PDA, with the aid of interface elements, not shown, and a bus connection, and is designed to communicate with the main computer.

[0029] With the aid of the central processing unit 7, arranging means 9 for arranging a communication mode, and generators 10 for generating at least one command signal, and first control elements 11 for transmitting a command-end signal CES that represents the end of the at least one generated command signal, and
- second control elements 12 and reception signal processing means 13 and sequence controllers 14 are realized; these items will be dealt with in greater detail below.

[0030] The station circuit 5 furthermore has generating means 15 for generating a carrier signal RS, and modulation elements 16 and demodulation elements 17. The modulation elements 16 are connected to the generating means 15 and the generators 10, and are designed for modulating the carrier signal RS with the command signals. Also contained in the station circuit 5 are encryption elements, not shown, which encryption elements are arranged before the modulation elements 16, in order to carry out encryption of the respective command signal before modulation.

[0031] The reader station 3 has station transmission means 18, these station transmission means 18 forming both transmitters and receivers, and which define the communication area CA in the case of transmission, and which in the present case are designed with a frequency of 13.56 MHz for the transmission of a communication station signal or reader signal RS', and which are designed for receiving a data carrier signal TS from the data carrier 2. Here, the station transmission means 18 are connected to the modulation elements 16 and demodulation elements 17. Such generating means 15, modulation elements 16, demodulation elements 17, station transmission means 18 and encryption elements are well known in specialist circles, for example from the document US 5 537 105 A1, the disclosure of which is deemed to be included here.

[0032] The reader station 3 furthermore has an accumulator 19 and an external power supply connection 20 and energy source recognition means 21, these energy source recognition means 21 being connected to the accumulator 19 and the external power supply connection 20, and being designed to emit a supply voltage V to the station circuit 5, as well as an energy source recognition signal ESS to the arranging means 9. In the present case, the energy source recognition means 21 are designed as electronic change-over switches,
wherein where an external energy source or external voltage source is present at the external power supply connection 20, this external voltage source is designed to supply the station circuit 5 with energy or voltage, and an energy source recognition signal ESS that represents this external voltage source is emitted; otherwise a switch-over to the accumulator 19 takes place and the station circuit 5 is supplied with the aid of the accumulator 19, and an energy source recognition signal ESS that represents the accumulator 19 is emitted.

[0033] In the present case, the data carrier 2 is a portion of a mobile phone and contains the circuit 4, as already mentioned. The circuit 4 is designed as an integrated circuit and contains a micro-computer 22. The micro-computer 22 contains a central processing unit 23 and storage media 24, this central processing unit 23 and storage media 24 working together in a familiar manner.

[0034] With the aid of the central processing unit 23, command signal recognition means 25 for recognizing a command signal COM that can be transmitted with the aid of the reader signal RS' of the reader station 3, and command/response command generators 26, and determination means 27, and sequence controllers 28 are realized; we shall deal with the means that are mentioned above and are realized with the central processing unit 23 in greater detail below.

[0035] The circuit 4 also has an oscillator 29 for producing and emitting a carrier signal TS of the data carrier 2, and first switching elements 30 and modulation elements 31 and detectors 32 for detecting the presence of the received carrier signal RS, which carrier signal RS was transmitted by the reader station 3 as reader signal RS', and demodulation elements 33 for demodulating the received carrier signal RS, and DC voltage generating means 34, and power supply change-over elements 35.

[0036] The data carrier 2 also has transmission means 36, these transmission means 36 forming both transmitters and receivers, and which define the communication area, not shown, of the data carrier in the case of transmission, which communication area of the data carrier includes the reader station 3. Also contained in the data carrier 2 is an accumulator 37, this accumulator 37 being connected to the power supply change-over elements 35 and serving to supply energy or voltage to the circuit 4 in one communication mode, which will be dealt with in greater detail below.

[0037] The mobile phone and the PDA are designed as so-called "Near Field Communication" (NFC) devices for an NFC communication system. In this NFC communication system, the mobile phone and the PDA are designed as communication partner appliances with equality of access, and both the mobile phone and the PDA can assume the role of an initiator, wherein when the role of initiator has been assumed by one of the two communication partner appliances, the other communication partner appliance respectively assumes the role of a target. Consequently in the present case, the functionality of the data carrier 2 and of the reader station 3, described above, is included in each of the two NFC devices, wherein for each NFC device, all the components required for the function of the data carrier 2 and the reader station 3 are included or realized jointly in an integrated circuit. It can be mentioned that all these components can be contained in two separate circuits.

[0038] Each of the two NFC devices or each of the two facilities follows a communication protocol for the role that has been assumed respectively, this communication protocol being stored in the respective storage media and being executed with the aid of the respective sequence controllers. In the present case, a communication protocol that is required for the function of the target is stored in a communication protocol storage area 38 of the storage media 24 of the data carrier 2, and can be executed with the aid of the sequence controllers 28 of the data carrier 2. Furthermore, a communication protocol that is required for the function of the initiator is stored in a communication protocol storage area of the station storage media 8 of the reader station 3, and can be executed with the aid of the sequence controllers 14 of the reader station 3. Each of the two NFC devices is envisaged to be able to work in an active communication mode or in a passive communication mode,
wherein for the target in the case of the active communication mode, a power supply for the circuit 4 is provided that is independent of the carrier signal RS, and in the case of the passive communication mode a power supply for the circuit 4 is provided that is dependent on the carrier signal RS. Such an active and passive communication mode is described for example in the published standard ECMA-340 of December 2002 (at http://www.ecma.ch or http://www.ecma-international.org/), whose disclosure in this regard is included herewith by reference.

[0039] An advantageous use of such an NFC device is described below on the basis of Figures 2 and 3.

[0040] Shown in Figure 2 is an entry-monitoring communication system 39, wherein in the present case the data carrier 2 contained in the PDA and a reader station 40 are shown. The reader station 40 and the data carrier 2 are designed for contact less communication according to a communication protocol defined in the standard ISO/IEC 14443, type A (MIFARE). It can be mentioned that a different communication protocol can be applied here, for example according to the standard ISO/IEC 14443, type B, ISO/IEC 15693, ISO/IEC 18000. The reader station 40 contains communication elements, not shown in further detail, for communicating with the device designed as a data carrier 2, these communication elements being disclosed for example in the document US20030128124 "Communication station for inventorizing transponders by means of selectable memory areas of the transponders", this disclosure being included herewith by reference.

[0041] In the present case, the entry-monitoring communication system 39 serves to monitor entry to a subway. For this instance, the data carrier 2 has entry authorization data, these entry authorization data being provided for access to and therefore use of the subway. The reader station 40 has a fixed electrical power supply and is operated in the passive communication mode. The term "passive communication mode" as applied to the reader station 40 is chosen not because the reader station 40 is supplied from a remotely located energy source, but because in the case of the passive communication mode of the reader station 40, the at least one data carrier 2 that is in communication connection with the reader station 40 is operated in its passive communication mode. In the present case, the PDA with the data carrier 2 located in it is brought into the communication area CA' of the reader station 40 by the user of the PDA. In accordance with the passive communication mode, the reader station 40 continuously transmits a reader signal RS, this reader signal RS being received by the transmission means 36 of the data carrier 2, and being transmitted to the detectors 32 and the demodulation elements 33 and the DC voltage production means 34. The DC voltage production means 34 are connected to the supply change-over elements 35 and are designed to deliver a supply voltage V in a familiar manner. In the present case, the supply change-over elements 35 are designed such that initially, the voltage that can be delivered by the DC voltage production means 34 serves to supply, the circuit 4. In the present case, in the event that the carrier signal RS reader station 40 is present, the detectors 32 transmit a carrier signal present signal PS to the determination means 27. The demodulation elements 33 are designed for demodulating the received reader signal RS and for transmitting the command signals that have been transmitted with the aid of the reader signal RS to the command signal recognition means 25. For example, in the present case an inventorizing command signal ICO is transmitted. The command signal recognition means 25 are designed to transmit a command-end signal CES that represents the end of the transmitted command signal to the determination means 27. The determination means 27 now establish whether, after the occurrence of the command-end signal CES, at a measurement point in time, the carrier signal present signal PS is present, wherein the determination means 27 transmit a first activation signal AS1 when the carrier signal present signal PS is present and otherwise, i.e. when the carrier signal present signal PS is not present, they transmit a second activation signal AS2. In the present case of the reader station 40 that is set according to the passive communication mode, after the command-end signal CES has been transmitted, the carrier signal present signal PS is present and the determination means 27 transmit the first activation signal AS1 to the switching elements 30 and the supply change-over elements 35. The supply change-over elements 35 are designed, on the basis of the first activation signal AS1, to switch over to the voltage for supplying the circuit 4 that is to be delivered by the DC voltage production means 34. The circuit 4 is thus switched into the passive communication mode, wherein an electrical power supply applies that depends on the reader signal RS, and advantageously the device's own limited power supply provided by the accumulator 37 is conserved.

[0042] A further advantageous use of such an NFC device is now described on the basis of Figure 3, in which Figure 3 a communication system 39b is shown. In the present case it is assumed that the user of the PDA in the subway becomes aware of an advertising poster for an event, further referred to as poster for short. The poster has a tag 41 as shown in Figure 3, this tag 41 containing event information about an event advertised on the poster and being designed for communicating in a passive communication mode. Such tags are well known in specialist circles, which is why they will not be elucidated further here. Also shown in Figure 3 is that portion of the PDA which, according to Figure 1, is designated as a reader station 3. In the present case, the reader station 3 is used for reading out the event information from the tag 41. Via the PDA's input means, not shown in further detail here, such as a keyboard in the present case, the reader station 3 is activated as an initiator, wherein on account of the circumstances the accumulator 19 is activated to provide the power supply for the circuit 5. The PDA or the reader station 3 is now brought into the vicinity of the poster, so that the tag 41 comes into the communication area CA of the reader station 3. The reader station 3 according to Figure 3 also has response signal detectors 42, these response signal detectors 42 being realized with the aid of the central processing unit 7. The response signal detectors 42 are connected to the reception signal processing means 13, and are provided for the detection of a response signal TS that is transmitted by the further communication partner appliance; when one is detected by the response signal detectors 42, a switch-over signal US can be generated, which switch-over signal US can be transmitted to the arranging means 9. Here, the arranging means 9 are designed automatically to set the communication mode depending on the switch-over signal US that has been generated.

[0043] If, as in the present case, the reader station 3 starts according to a protocol for the active communication mode, the tag 41 will not emit a response signal TS and consequently no response signal TS will be received in the reader station 3 and processed. Subsequently, with the aid of the response signal detectors 42, the switch-over signal US is generated and transmitted to the arranging means 9, whereupon the reader station 3 switches into the passive communication mode that is appropriate for communicating with the tag 41. The event information can now be read out in the customary manner from the tag 41, and then stored in the station storage media 8 for further use.

[0044] Such further use is now described on the basis of Figure 1. In the present case it is assumed that the user of the PDA wishes to draw a friend's attention to the aforementioned event and wishes to convey the event information to that friend. This is to take place by means of the aforementioned mobile phone. For this, the event information stored in the PDA or station storage media 8 of the reader station 3 is transmitted to the mobile phone. The PDA or the reader station 3 can, as mentioned above, be activated by means of input means and assumes the role of initiator. The mobile phone with the data carrier 2 contained therein is brought into the communication area CA. As already mentioned in connection with Figure 2, in the data carrier 2 the supply change-over elements 35 are designed such that initially, the voltage that can be delivered by the DC voltage production means 34 serves to supply the circuit 4. On account of the power supply by the accumulator 37, the reader station 3 is first of all operated in the active communication mode. The subsequent communication sequence is now described on the basis of Figure 4.

[0045] As is shown in Figure 4, from a first point in time t1 onwards, the carrier signal RS is generated and is then transmitted as a reader signal RS'. From a second time point t2 to a third time point t3, in the generators 10 of the reader station 3 a command signal COM is generated and is emitted as a modulated signal with the carrier signal RS. The first control elements 11 transmit a command-end signal CES of the reader station 3 that represents the end of the generated command signal COM to the second control elements 12, whereupon the second control elements 12 initiate the situation that after a time period TPR after the occurrence of each command-end signal, the carrier signal RS is switched off by the command-end signal CES of the reader station 3 in the production means 15, or is no longer generated, and consequently no reader signal RS' is transmitted to the data carrier 2. The time period TPR corresponds in the present case to a period duration of 30 oscillations of the carrier signal or reader signal RS. It can be mentioned that the time period TPR can be greater, for example 60 or 90 oscillations of the carrier signal, or smaller, for example just 10 or 20 oscillations of the carrier signal. What is important here is that the detectors 32 have sufficient time to be able safely and reliably to recognize whether the carrier signal RS' is present or no longer present or switched off.

[0046] The switching off of the carrier signal RS takes place at a fourth point in time t4 in accordance with Figure 4. It can be mentioned that interrupt elements for interrupting the transmission of the reader signal RS' can be arranged between the modulation elements 16 and the transmission means 18, and these interrupt elements can then be activated by the second control elements 12 for interruption.

[0047] As has already been mentioned, the detectors 32 of the data carrier 2 are designed to detect the presence of the received carrier signal RS. The detectors 32 are furthermore designed to emit or transmit a carrier signal present signal PS in the event that the carrier signal RS is present, and otherwise to emit or transmit a carrier signal not-present signal NPS. In the present case, in Figure 4 the time dependent behavior of the carrier signal present signal PS is shown, wherein such a carrier signal present signal PS is no longer transmitted from the fourth time point t4 onwards. Furthermore, the command signal recognition means 25 of the data carrier 2 are designed to recognize a command signal that can be transmitted with the aid of the carrier signal RS, and to emit a command-end signal CES that represents the end of the transmitted command signal. Shown in Figure 4 is the time dependent behavior for the command-end signal CES of the data carrier 2 for the present case, wherein from the third time point t3 onwards, i. e. after the end of the command signal COM transmitted by the reader station 3, the command-end signal CES is shown as a short pulse. In the determination means 27, triggered by the command-end signal CES, after a time period DTP it is established whether, after the occurrence of the command-end signal CES, at a measurement point in time, as in this case after the expired time period DTP at a fifth point in time t5, the carrier signal present signal PS is present. In the present case the time period DTP lasts for 60 oscillations or periods of the carrier signal RS. It can be mentioned that the time period DTP can be of a different duration, for example three or four times the duration of the time period TPR. According to the present circumstances, the determination means 27 transmit the second activation signal AS2, since at the fifth point in time t5 no carrier signal present signal PS is present. Subsequently, with the aid of the second activation signal AS2 the circuit 4 is brought into the second communication mode with the aid of the activators, i. e. in the present case into the active communication mode, wherein for this the supply change-over elements 35 are controlled such that the power supply for the circuit 4 is provided by the accumulator 37, and wherein the first switching elements 30 are controlled such that a carrier signal for generating the data carrier signal TS can be transmitted by the oscillator 29 in a familiar manner to the modulation elements 31 of the data carrier 2.

[0048] It can be mentioned that instead of the aforementioned PDA, the aforementioned mobile phone can be used to read out such a tag 41, wherein the event information can then be transmitted to the PDA, and in the course of this the mobile phone can take on the role of the reader station 3.

[0049] It should furthermore be mentioned that instead of the mobile phone or PDA, other devices can be designed as NFC devices, for example a laptop, a watch, a digital camera, a camcorder and much else besides. Thus for example it can be the case that with such a watch designed as an NFC, the type of event information mentioned above can be polled and subsequently this event information can be conveyed to the laptop, for example for the purpose of managing appointments. The laptop can optionally be connected to a power supply mains network or operated independently of the mains supply, with an accumulator. Depending on the electricity or power supply situation of the laptop, corresponding communication can be initiated in the passive communication mode or active communication mode, as has been explained above.

[0050] It should furthermore be mentioned that the reader signal RS' and the data carrier signal TS can lie in another frequency range, for example at a frequency of 125 kHz.

[0051] It should furthermore be mentioned that influencing means for influencing a signal strength of the carrier signal RS depending on the set communication mode can be provided in the reader station 3 and/or in the data carrier 2. Thus the influencing means can for example be designed such that in the active communication mode, the reader signal RS' is transmitted with a low field strength, through which the device's own power supply that is used in the case of the active communication mode can be conserved.

Claims

1. A circuit (4), this circuit (4) being provided for a communication partner appliance (2) that is designed for contact less communication and as a data carrier, this communication partner appliance (2) being provided for a communication system with at least one further communication partner appliance (3), in which circuit (4) a passive communication mode or an active communication mode can be activated, and which circuit (4) has the means listed below:

- activators (30,35) for activating the passive communication mode or the active communication mode, and

- reception means (36) for receiving a carrier signal that is transmitted by the at least one further communication partner appliance (3),

- and detectors (32) for detecting the presence of the received carrier signal (RS), these detectors (32) transmitting a carrier signal present signal (PS) in the event that the carrier signal (RS) is present, and otherwise transmitting a carrier signal not-present signal (NPS), and

- command signal recognition means (25) for recognizing a command signal that can be transmitted with the aid of the carrier signal (RS) and for transmitting a command-end signal (CES) that represents the end of the transmitted command signal, and

- determination means (27) for determining whether, after the occurrence of the command-end signal (CES), at a given measurement point in time (t5), the carrier signal present signal (PS) is present, with which determination means (27) a first activation signal (AS1) can be transmitted when the carrier signal present signal (PS) is present, and otherwise a second activation signal (AS2) can be transmitted, with which first activation signal (AS1) the circuit (4) can be brought into the passive communication mode with the aid of the activators (30,35), and with which second activation signal (AS2) the circuit (4) can be brought into the active communication mode with the aid of the activators (30,35), wherein said given measurement point in time (t5) is given by the time said detectors (32) require to recognize, whether said carrier signal (RS) is present or no longer present or switched off.

2. A circuit (4) as claimed in claim 1, wherein in the case of the active communication mode, a power supply for the circuit (4) is provided that is independent of the carrier signal (RS), and in the case of the passive communication mode, a power supply for the circuit (4) is provided that is dependent on the carrier signal (RS).

3. A circuit (4) as claimed in claim 2, wherein a battery or accumulator (37) is provided for the independent power supply.

4. A communication partner appliance (2) that is designed as a data carrier and is equipped with a circuit (4) as claimed in any one of the claims 1 to 3.

5. A circuit (5), this circuit (5) being provided for a communication partner appliance (3) that is designed for contact less communication and as a communication station, this communication partner appliance (3) being provided for a communication system with at least one further communication partner appliance (2), in which further communication partner appliance (2) a passive communication mode or an active communication mode can be activated, this circuit (5) containing the means listed below:

- production means (15) for producing a carrier signal (RS), and

- transmission means (18) for transmitting the carrier signal (RS) to the further communication partner appliance (2), and

- arranging means (9) for arranging a communication mode, and

- a generator (10) for generating at least one command signal, which command signal can be transmitted to the further communication partner appliance (2) with the aid of the carrier signal (RS), and

- first control elements (11) for transmitting a command-end signal (CES) that represents the end of the generated command signal, and

- second control elements (12), with which second control elements (12), after the occurrence of the command-end signal (CES), the generation and/or transmission of the carrier signal (RS) can be ended at a particular point in time (t4).

6. A circuit (5) as claimed in claim 5, wherein the arranging means (9) are designed for the optional arrangement of an active communication mode or a passive communication mode, in which active communication mode the further communication partner appliance (2) has a power supply that is independent of the carrier signal (RS), and in which passive communication mode the further communication partner appliance (2) has a power supply that is dependent on the carrier signal (RS).

7. A circuit (5) as claimed in any one of the claims 5 or 6, wherein energy source recognition means (21) are provided, these energy source recognition means (21) being adapted to recognize an energy source for supplying power to the circuit (5), and with which energy source recognition means (21) an energy source recognition signal can be transmitted depending on the energy source that has been recognized, and wherein the arranging means (9) are designed to arrange the communication mode depending on the energy source recognition signal.

8. A circuit (5) as claimed in any one oft the claims 5 to 7, wherein response signal detectors (42) are provided, for detecting a response signal (TS) transmitted by the further communication partner appliance (2), in the course of which detection a change-over signal (US) can be generated, and wherein the arranging means (9) are designed to automatically arrange the communication mode depending on the change-over signal (US) that has been generated.

9. A circuit (5) as claimed in any one oft the claims 5 to 8, wherein influencing means are provided for influencing a signal strength of the carrier signal (RS) depending on the arranged communication mode.

10. A communication partner appliance (3) that is designed as a communication station and is equipped with a circuit (5) as claimed in any one of the claims 5 to 9.

11. A method for activating a passive communication mode or an active communication mode of a communication partner appliance (2), wherein the communication partner appliance (2) is provided for a communication system with at least one further communication partner appliance (3), and wherein a carrier signal (RS) is transmitted by the at least one further communication partner appliance (3), this carrier signal (RS) being received with the communication partner appliance (2), and

- wherein in the communication partner appliance (2), detection of the presence of the received carrier signal (RS) takes place, and in the event of the carrier signal (RS) being present, a carrier signal present signal (PS) is transmitted, and otherwise a carrier signal not-present signal (NPS) is transmitted, and

- wherein recognition of a command signal (ICO) that can be transmitted with the aid of the carrier signal (RS) takes place, and transmission of a command-end signal (CES) that represents the end of the transmitted command signal (ICO) takes place, and wherein determination is carried out to see whether, after the occurrence of the command-end signal (CES), at a measurement point in time (t5), the carrier signal present signal (PS) is present, wherein a first activation signal (AS1) is transmitted when the carrier signal present signal (PS) is present, and otherwise a second activation signal (AS2) is transmitted, and wherein with the first activation signal (AS1), activation of the communication partner appliance (2) into the passive communication mode is carried out, or with the second activation signal (AS2), activation of the communication partner appliance (2) into the active communication mode is carried out, wherein said given measurement point in time (t5) is given by the time said detectors (32) require to recognize, whether said carrier signal (RS) is present or no longer present or switched off.

12. A device, this device having a circuit (4) as claimed in any one of the claims 1 to 4 and a circuit (5) as claimed in any one of the claims 5 to 10.

13. A device as claimed in claim 12, wherein the circuit (4) as claimed in any one of the claims 1 to 4 and the circuit (5) as claimed in any one of the claims 5 to 10 are realized in a single circuit.

Ansprüche

1. Eine Schaltung (4), wobei diese Schaltung (4) für eine Kommunikationspartneranwendung (2) bereitgestellt ist, die zur kontaktlosen Kommunikation und als ein Datenträger konzipiert ist, wobei diese Kommunikationspartneranwendung (2) für ein Kommunikationssystem mit zumindest einer weiteren Kommunikationspartneranwendung (3) bereitgestellt ist, wobei in der Schaltung (4) ein passiver Kommunikationsmodus oder ein aktiver Kommunikationsmodus aktivierbar ist und wobei die Schaltung (4) die folgenden Mittel aufweist:

- Aktivatoren (30, 35) zum Aktivieren des passiven Kommunikationsmodus oder des aktiven Kommunikationsmodus,

- Empfangsmittel (36) zum Empfangen eines Trägersignals, das von der zumindest einen weiteren Kommunikationspartneranwendung (3) übertragen wird,

- und Detektoren (32) zum Erkennen des Vorhandenseins des empfangenen Trägersignals (RS), wobei diese Detektoren (32) ein Trägersignal-Vorhanden-Signal (PS) übertragen, sofern das Trägersignal (RS) vorhanden ist, und andernfalls ein Trägersignal-Nicht-Vorhanden-Signal (NPS) übertragen, und

- Befehlssignalerkennungsmittel (25) zum Erkennen eines Befehlssignals, das mit Hilfe des Trägersignal (RS) übertragbar ist, und zum Übertragen eines Befehlsendsignals (CES), welches das Ende des übertragenen Befehlssignals darstellt, und

- Bestimmungsmittel (27) zum Bestimmen, ob nach dem Auftreten des Befehlsendsignals (CES) zu einem vorgegebenen Messzeitpunkt (t5) das Trägersignal-Vorhanden-Signal (PS) vorhanden ist, wobei mit den Bestimmungsmitteln (27) ein erstes Aktivierungssignal (AS1) übertragbar ist, sofern das Trägersignal-Vorhanden-Signal (PS) vorhanden ist, und andernfalls ein zweites Aktivierungssignal (AS2) übertragbar ist, wobei die Schaltung (4) mit dem ersten Aktivierungssignal (AS1) mit Hilfe der Aktivatoren (30, 35) in den passiven Kommunikationsmodus versetzt werden kann und wobei die Schaltung (4) mit dem zweiten Aktivierungssignal (AS2) mit Hilfe der Aktivatoren (30,35) in den aktiven Kommunikationsmodus versetzt werden kann, wobei der vorgegebene Messzeitpunkt (t5) durch die Zeit vorgegeben ist, welche die Detektoren (32) benötigen, um zu erkennen, ob das Trägersignal (RS) vorhanden oder nicht mehr vorhanden oder abgeschaltet ist.

2. Eine Schaltung (4) nach Anspruch 1, wobei im Fall des aktiven Kommunikationsmodus eine vom Trägersignal (RS) unabhängige Energiequelle für die Schaltung (4) bereitgestellt wird und im Fall des passiven Kommunikationsmodus eine vom Trägersignal (RS) abhängige Energiequelle für die Schaltung (4) bereitgestellt wird.

3. Eine Schaltung (4) nach Anspruch 2, wobei eine Batterie oder ein Akkumulator (37) für die unabhängige Energiequelle bereitgestellt ist.

4. Eine Kommunikationspartneranwendung (2), die als ein Datenträger konzipiert ist und mit einer Schaltung (4) nach einem der Ansprüche 1 bis 3 ausgestattet ist.

5. Eine Schaltung (5), wobei diese Schaltung (5) für eine Kommunikationspartneranwendung (3) bereitgestellt ist, die zur kontaktlosen Kommunikation und als eine Kommunikationsstation konzipiert ist, wobei diese Kommunikationspartneranwendung (3) für ein Kommunikationssystem mit zumindest einer weiteren Kommunikationspartneranwendung (2) bereitgestellt ist, wobei in der weiteren Kommunikationspartneranwendung (2) ein passiver Kommunikationsmodus oder ein aktiver Kommunikationsmodus aktivierbar ist, wobei diese Schaltung (5) die folgenden Mittel umfasst:

- Erzeugungsmittel (15) zum Erzeugen eines Trägersignals (RS) und

- Übertragungsmittel (18) zum Übertragen des Trägersignals (RS) an die weitere Kommunikationspartneranwendung (2) und

- Einrichtungsmittel (9) zum Einrichten eines Kommunikationsmodus und

- einen Generator (10) zum Generieren von zumindest einem Befehlssignal, wobei das Befehlssignal mit Hilfe des Trägersignals (RS) an die weitere Kommunikationspartneranwendung (2) übertragbar ist, und

- erste Steuerelemente (11) zum Übertragen eines Befehlsendsignals (CES), welches das Ende des generierten Befehlssignals darstellt, und

- zweite Steuerelemente (12), wobei mit den zweiten Steuerelementen (12) nach dem Auftreten des Befehlsendsignals (CES) die Erzeugung und/oder Übertragung des Trägersignals (RS) zu einem bestimmten Zeitpunkt (t4) beendet werden kann.

6. Eine Schaltung (5) nach Anspruch 5, wobei die Einrichtungsmittel (9) für die optionale Einrichtung eines aktiven Kommunikationsmodus oder eines passiven Kommunikationsmodus konzipiert sind, wobei die weitere Kommunikationspartneranwendung (2) im aktiven Kommunikationsmodus eine vom Trägersignal (RS) unabhängige Energiequelle aufweist und wobei die weitere Kommunikationspartneranwendung (2) im passiven Kommunikationsmodus eine vom Trägersignal (RS) abhängige Energiequelle aufweist.

7. Eine Schaltung (5) nach einem der Ansprüche 5 oder 6, wobei Energiequellenerkennungsmittel (21) bereitgestellt sind, wobei diese Energiequellen-Erkennungsmittel (21) so gestaltet sind, dass sie eine Energiequelle zum Bereitstellen von Energie für die Schaltung (5) erkennen, und wobei mit den Energiequellenerkennungsmitteln (21) in Abhängigkeit von der erkannten Energiequelle ein Energiequellenerkennungssignal übertragbar ist und wobei die Einrichtungsmittel (9) so konzipiert sind, dass sie den Kommunikationsmodus in Abhängigkeit vom Energiequellenerkennungssignal einrichten.

8. Eine Schaltung (5) nach einem der Ansprüche 5 bis 7, wobei Antwortsignaledetektoren (42) zum Erkennen eines von der weiteren Kommunikationspartneranwendung (2) übertragenen Antwortsignals (TS) bereitgestellt sind, wobei während der Erkennung ein Umschaltsignal (US) generierbar ist und wobei die Einrichtungsmittel (9) so konzipiert sind, dass sie den Kommunikationsmodus in Abhängigkeit vom generierten Umschaltsignal (US) automatisch einrichten.

9. Eine Schaltung (5) nach einem der Ansprüche 5 bis 8, wobei Beeinflussungsmittel zum Beeinflussen einer Signalstärke des Trägersignals (RS) in Abhängigkeit vom eingerichteten Kommunikationsmodus bereitgestellt sind.

10. Eine Kommunikationspartneranwendung (3), die als eine Kommunikationsstation konzipiert ist und mit einer Schaltung (5) nach einem der Ansprüche 5 bis 9 ausgestattet ist.

11. Ein Verfahren zum Aktivieren eines passiven Kommunikationsmodus oder eines aktiven Kommunikationsmodus einer Kommunikationspartneranwendung (2), wobei die Kommunikationspartneranwendung (2) für ein Kommunikationssystem mit zumindest einer weiteren Kommunikationspartneranwendung (3) bereitgestellt ist, und wobei ein Trägersignal (RS) durch die zumindest eine weitere Kommunikationspartneranwendung (3) übertragen wird, wobei dieses Trägersignal (RS) mit der Kommunikationspartneranwendung (2) empfangen wird, und

- wobei in der Kommunikationspartneranwendung (2) die Erkennung des Vorhandenseins des empfangenen Trägersignal (RS) stattfindet und im Fall, dass das Trägersignal (RS) vorhanden ist, ein Trägersignal-Vorhanden-Signal (PS) übertragen wird und andernfalls ein Trägersignal-Nicht-Vorhanden-Signal (NPS) übertragen wird, und

- wobei die Erkennung eines mit Hilfe des Trägersignals (RS) übertragbaren Befehlssignals (ICO) stattfindet und die Übertragung eines das Ende des übertragenen Befehlssignals (ICO) darstellenden Befehlsendsignals (CES) stattfindet und wobei ermittelt wird, ob nach dem Auftreten des Befehlsendsignals (CES) zu einem Messzeitpunkt (t5) das Trägersignal-Vorhanden-Signal (PS) vorhanden ist, wobei ein erstes Aktivierungssignal (AS1) übertragen wird, sofern das Trägersignal-Vorhanden-Signal (PS) vorhanden ist, und andernfalls ein zweites Aktivierungssignal (AS2) übertragen wird, und wobei mit dem ersten Aktivierungssignal (AS 1) die Kommunikationspartneranwendung (2) in den passiven Kommunikationsmodus versetzt wird oder mit dem zweiten Aktivierungssignal (AS2) die Kommunikationspartneranwendung (2) in den aktiven Kommunikationsmodus versetzt wird, wobei der vorgegebene Messzeitpunkt (t5) durch die Zeit vorgegeben ist, welche die Detektoren (32) benötigen, um zu erkennen, ob das Trägersignal (RS) vorhanden oder nicht mehr vorhanden oder abgeschaltet ist.

12. Eine Vorrichtung, wobei diese Vorrichtung eine Schaltung (4) nach einem der Ansprüche 1 bis 4 und eine Schaltung (5) nach einem der Ansprüche 5 bis 10 aufweist.

13. Eine Vorrichtung nach Anspruch 12, wobei die Schaltung (4) nach einem der Ansprüche 1 bis 4 und die Schaltung (5) nach einem der Ansprüche 5 bis 10 in einer einzigen Schaltung ausgeführt sind.

Revendications

1. Circuit (4), ce circuit (4) étant fourni pour un appareil partenaire de communication (2) qui est conçu pour une communication sans contact et en tant que support de données, cet appareil partenaire de communication (2) étant fourni pour un système de communication avec au moins un autre appareil partenaire de communication (3), circuit (4) dans lequel on peut activer un mode de communication passif ou un mode de communication actif, et lequel circuit (4) a les moyens énumérés ci-dessous :

- des activateurs (30, 35) pour activer le mode de communication passif ou le mode de communication actif, et

- des moyens de réception (36) pour recevoir un signal de porteuse qui est émis par ledit au moins un autre appareil partenaire de communication (3),

- et des détecteurs (32) pour détecter la présence du signal de porteuse reçu (RS), ces détecteurs (32) transmettant un signal de présence de signal de porteuse (PS) dans le cas où le signal de porteuse (RS) est présent, et transmettant sinon un signal de non-présence de signal de porteuse (NPS), et

- des moyens de reconnaissance de signal de commande (25) pour reconnaitre un signal de commande qui peut être transmis à l'aide du signal de porteuse (RS) et pour transmettre un signal de fin de commande (CES) qui représente la fin du signal de commande transmis, et

- des moyens de détermination (27) pour déterminer si, après l'occurrence du signal de fin de commande (CES), en un point de mesure donné dans le temps (t5), le signal de présence de signal de porteuse (PS) est présent, grâce auxquels moyens de détermination (27) un premier signal d'activation (AS 1) peut être transmis lorsque le signal de présence de signal de porteuse (PS) est présent, et sinon, un deuxième signal d'activation (AS2) peut être transmis, grâce auquel premier signal d'activation (AS1) le circuit (4) peut être placé dans le mode de communication passif à l'aide des activateurs (30, 35), et grâce auquel deuxième signal d'activation (AS2) le circuit (4) peut être placé dans le mode de communication actif à l'aide des activateurs (30, 35), dans lequel ledit point de mesure donné dans le temps (t5) est défini par le temps qui est nécessaire pour que lesdits détecteurs (32) reconnaissent si ledit signal de porteuse (RS) est présent ou s'il ne l'est plus ou s'il est coupé.

2. Circuit (4) selon la revendication 1, où, dans le cas du mode de communication actif, est fournie une alimentation pour le circuit (4) qui est indépendante du signal de porteuse (RS), et dans le cas du mode de communication passif, est fournie une alimentation pour le circuit (4) qui est dépendante du signal de porteuse (RS).

3. Circuit (4) selon la revendication 2, dans lequel une pile ou un accumulateur (37) est fourni pour la source d'alimentation indépendante.

4. Dispositif partenaire de communication (2) qui est conçu comme support de données et est équipé d'un circuit (4) selon l'une quelconque des revendications 1 à 3.

5. Circuit (5), ce circuit (5) étant fourni pour un appareil partenaire de communication (3) qui est conçu pour une communication sans contact et en tant que station de communication, cet appareil partenaire de communication (3) étant fourni pour un système de communication avec au moins un autre appareil partenaire de communication (2), appareil partenaire de communication (2) dans lequel on peut activer un mode de communication passif ou un mode de communication actif, ce circuit (5) ayant les moyens énumérés ci-dessous :

- des moyens de génération (15) pour produire un signal de porteuse (RS), et

- des moyens de transmission (18) pour transmettre le signal de porteuse (RS) à l'autre appareil partenaire de communication (2), et

- des moyens d'agencement (9) pour agencer un mode de communication, et

- un générateur (10) pour générer au moins un signal de commande, lequel signal de commande peut être transmis à l'autre appareil partenaire de communication (2) à l'aide du signal de porteuse (RS), et

- des premiers éléments de contrôle (11) pour transmettre un signal de fin de commande (CES) qui représente la fin du signal de commande généré, et

- des deuxièmes éléments de contrôle (12), grâce auxquels deuxièmes éléments de contrôle (12), après l'apparition du signal de fin de commande (CES), la génération et/ou la transmission du signal de porteuse (RS) peut être terminée en un point particulier dans le temps (t4).

6. Circuit (5) selon la revendication 5, dans lequel les moyens d'agencement (9) sont conçus pour l'agencement facultatif d'un mode de communication actif ou d'un mode de communication passif, dans lequel mode de communication actif, l'autre appareil partenaire de communication (2) a une alimentation qui est indépendante du signal de porteuse (RS), et dans le cas d'un mode de communication passif, l'autre appareil partenaire de communication (2) a une alimentation qui est dépendante du signal de porteuse (RS).

7. Circuit (5) selon l'une quelconque des revendications 5 ou 6, dans lequel sont fournis des moyens de reconnaissance de la source d'énergie (21), ces moyens de reconnaissance de la source d'énergie (21) étant agencés de manière à reconnaitre une source d'énergie pour fournir une alimentation au circuit (5), et avec lesquels moyens de reconnaissance de la source d'énergie (21) peut être transmis un signal de reconnaissance de source d'énergie en fonction de la source d'énergie qui a été reconnue, et dans lequel les moyens d'agencement (9) sont conçus pour agencer le mode de communication en fonction du signal de reconnaissance de la source d'énergie.

8. Circuit (5) selon l'une quelconque des revendications 5 à 7, dans lequel sont fournis des détecteurs de signal de réponse (42), pour détecter un signal de réponse (TS) transmis par l'autre appareil partenaire de communication (2), détection au cours de laquelle un signal de basculement (US) peut être généré, et dans lequel les moyens d'agencement (9) sont conçus pour agencer automatiquement le mode de communication en fonction du signal de basculement (US) qui a été généré.

9. Circuit (5) selon l'une quelconque des revendications 5 à 8, dans lequel sont disposés des moyens d'influence pour influencer une puissance de signal du signal de porteuse (RS) en fonction du mode de communication agencé.

10. Appareil partenaire de communication (3) qui est conçu comme station de communication et est équipé d'un circuit (5) selon l'une quelconque des revendications 5 à 9.

11. Procédé d'activation d'un mode de communication passif ou d'un mode de communication actif d'un appareil partenaire de communication (2), dans lequel l'appareil partenaire de communication (2) est fourni pour un système de communication avec au moins un autre appareil partenaire de communication (3), et dans lequel un signal de porteuse (RS) est transmis par au moins un autre appareil partenaire de communication (3), ce signal de porteuse (RS) étant reçu avec l'appareil partenaire de communication (2), et

- dans lequel intervient dans l'appareil partenaire de communication (2) une détection de la présence du signal de porteuse reçu (RS), et dans le cas où le signal de porteuse (RS) est présent, un signal de présence de signal de porteuse (PS) est transmis, et sinon un signal de non-présence de signal de porteuse (NPS) est transmis, et

- dans lequel intervient la reconnaissance d'un signal de commande (ICO) qui peut être transmis à l'aide du signal de porteuse (RS), et la transmission d'un signal de fin de commande (CES) qui représente la fin du signal de commande transmis (ICO), et dans lequel on réalise une détermination pour savoir si, après l'occurrence du signal de fin de commande (CES), en un point de mesure donné dans le temps (t5), le signal de présence de signal de porteuse (PS) est présent, dans lequel un premier signal d'activation (AS1) est transmis lorsque le signal de présence de signal de porteuse (PS) est présent, et sinon, un deuxième signal d'activation (AS2) est transmis et dans lequel, grâce au premier signal d'activation (AS1), on place l'appareil partenaire de communication (2) dans le mode de communication passif, ou grâce au deuxième signal d'activation (AS2) on place l'appareil partenaire de communication (2) dans le mode de communication actif, dans lequel ledit point de mesure donné dans le temps (t5) est défini par le temps qui est nécessaire pour que lesdits détecteurs (32) reconnaissent si ledit signal de porteuse (RS) est présent ou s'il ne l'est plus ou s'il est coupé.

12. Appareil, cet appareil ayant un circuit (4) selon l'une quelconque des revendications 1 à 4 et un circuit (5) selon l'une quelconque des revendications de 5 à 10.

13. Appareil selon la revendication 12, dans lequel le circuit (4) selon l'une quelconque des revendications 1 à 4 et le circuit (5) selon l'une quelconque des revendications 5 à 10 sont réalisés dans un circuit unique.

Drawing